[1307] updated the RRsetMatch logic so that we can differentiate RRSIGs

of different types covered.  Not directly related to the main subject
of the branch, but this enhancement will make writing tests easier.
confirmed this change doesn't cause regression for other tests.

src/lib/testutils/dnsmessage_test.h

@@ -21,6 +21,7 @@
 #include <dns/message.h>
 #include <dns/name.h>
 #include <dns/masterload.h>
+#include <dns/rdataclass.h>
 #include <dns/rrclass.h>
 #include <dns/rrset.h>
 
@@ -113,13 +114,32 @@ void rrsetCheck(isc::dns::ConstRRsetPtr expected_rrset,
 /// The definitions in this name space are not supposed to be used publicly,
 /// but are given here because they are used in templated functions.
 namespace detail {
-// Helper matching class used in rrsetsCheck()
+// Helper matching class used in rrsetsCheck().  Basically we only have to
+// check the equality of name, RR type and RR class, but for RRSIGs we need
+// special additional checks because they are essentially different if their
+// 'type covered' are different.  For simplicity, we only compare the types
+// of the first RRSIG RDATAs (and only check when they exist); if there's
+// further difference in the RDATA, the main comparison checks will detect it.
 struct RRsetMatch : public std::unary_function<isc::dns::ConstRRsetPtr, bool> {
     RRsetMatch(isc::dns::ConstRRsetPtr target) : target_(target) {}
     bool operator()(isc::dns::ConstRRsetPtr rrset) const {
-        return (rrset->getType() == target_->getType() &&
-                rrset->getClass() == target_->getClass() &&
-                rrset->getName() == target_->getName());
+        if (rrset->getType() != target_->getType() ||
+            rrset->getClass() != target_->getClass() ||
+            rrset->getName() != target_->getName()) {
+            return (false);
+        }
+        if (rrset->getType() != isc::dns::RRType::RRSIG()) {
+            return (true);
+        }
+        if (rrset->getRdataCount() == 0 || target_->getRdataCount() == 0) {
+            return (true);
+        }
+        isc::dns::RdataIteratorPtr rdit = rrset->getRdataIterator();
+        isc::dns::RdataIteratorPtr targetit = target_->getRdataIterator();
+        return (dynamic_cast<const isc::dns::rdata::generic::RRSIG&>(
+                    rdit->getCurrent()).typeCovered() ==
+                dynamic_cast<const isc::dns::rdata::generic::RRSIG&>(
+                    targetit->getCurrent()).typeCovered());
     }
     const isc::dns::ConstRRsetPtr target_;
 };